1. Field of the Invention
The present invention relates to a wrench having a universal-joint ratchet wheel, and more particularly to a wrench having a box end in which a universal-joint ratchet wheel is mounted.
2. Description of the Related Art
Wrenches have been widely used and most of them are limited in function especially when the fasteners to be loosened or tightened are located in a difficult-to-access area. The present invention is intended to provide an improved design to solve this problem.
It is the primary object of the present invention to provide an improved wrench having a box end in which a universal-joint ratchet wheel is mounted. The universal-joint ratchet wheel allows the user to loosen/tighten fasteners that cannot be engaged with the wrench in an upright manner.
A wrench comprising:
a box end comprising a compartment and a cavity;
a ratchet wheel rotatably mounted in the compartment, an inner periphery defining the compartment of the box end allowing universal movement of the ratchet wheel, the ratchet wheel including a plurality of teeth on an outer periphery thereof;
a pawl mounted in the cavity for engaging with the ratchet wheel;
means for biasing the pawl toward the ratchet wheel and thus engaging with the teeth of the ratchet wheel;
the ratchet wheel being completely received in the compartment of the box end when a central axis of the ratchet wheel is coincident with a central axis of the compartment of the box end.
The wrench further comprises means for restraining a tilt angle of the central axis of the ratchet wheel relative to the central axis of the compartment of the box end. The ratchet wheel includes an inner polygonal periphery for engaging with a fastener. The wrench may further comprise means for changing position of the pawl relative to the ratchet wheel, thereby changing the ratcheting direction of the wrench. The outer periphery of the ratchet wheel includes an annular groove for receiving a C-clip to thereby rotatably mount the ratchet wheel in the compartment of the box end. The outer periphery of the ratchet wheel includes an annular ledge formed on an end thereof for engaging with the pawl to prevent disengagement of the ratchet wheel from the compartment of the box end. Alternatively, the outer periphery of the ratchet wheel includes a first annular ledge and a second annular ledge that is axially spaced from the first annular ledge, each of the first annular ledge and the second annular ledge being engagable with the pawl to prevent disengagement of the ratchet wheel from the compartment of the box end.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.